you need a microUSB ---> Composite Video/Right Audio/Left Audo
If you have one already...it may OR may not work depending upon how the cable is wired.
this video
shows the cable in use.
note: at the beginning of the video there is a bubble that says
"Second microUSB port for charging while connected"
So it looks like the microUSB side of the cable has both a male and female. The male for plugging into the Incredible and the female to receive the charger.
I have never seen a cable like this before...and I have seen just about everything (i work in the entertainment technology field).
my advise is the wait for the official release of the cable which will be "post launch" according to the verizon launch package pdf
also in the verizon launch package pdf the "TV Out" cable shows a picture of a 3.5mm jack as the male portion of the plub...they must have used a stock photo because the "TV Out" definitely connects to the phone via microUSB